Ph.D. Tezi Görüntüleme | |||||||||||||||||||||
|
|
||||||||||||||||||||
| Summary: The objective of this study was to investigate the changes created by weathering on impregnated wood with CCA and alternative wood preservatives. Natural weathering factors were simulated at laboratory conditions. The weathering experiment was performed by cycles of UV-light irradiation followed by water spray. This was performed study; accelerated weathering using UV irradiation and water spray was used to simulate natural weathering. The changes on the surface of the weathered samples were characterized by Fourier Transform Infrared spectroscopy for chemical changes, color measurements, surface roughness and microscopic studies on the samples with 0, 200, 400 and 600 hours of total weathering. Treated and untreated samples were exposed to decay fungus, using C. puteana, C. versicolor and P. placenta in order to determining decay resistance of samples. In addition, terrestrial microcosms and soil-bed test, based on changing weight loss and modulus of elasticity were carried out.Leaching of wood preservatives was done according to AWPA E 11-97 standard for determining copper emission from preservative treated wood to the environment. The analysis of copper in treated wood blocks and in the leachate was measured by an Atomic Absorption Spectrometer. As a conclusion; when wood is exposed to UV light, photochemical degradation is manifested by an initial color changes, followed by formation of carbonyl groups and quinones. Copper containing wood preservatives slowed photodegradation and stabilized wood surface against UV light. After decay test, it was found that copper has excellent fungicidal characteristics. In addition, wood materials used outside conditions must be treated with wood preservatives. Generally, CCA and ACQ-1900 wood preservatives were found better protection than other copper containing wood preservatives. However, CCA had been banned or restricted its use in most countries.Keywords: Weathering Factors, Copper Containing Wood Preservatives, Photodegradation, Leaching, Decay Test.
| |||||||||||||||||||||